Table 2.

Nucleotide substitutions inbla TEM-2, bla TEM-21, and bla TEM-56 genes

Region and nucleotide positionaNucleotide in:
blaTEM-2blaTEM-21blaTEM-56
Promoter region
 32* b TTT
 175* AAA
Coding region
 226* CCC
 317* A (Lys-39c)AA
 346* GGG
 436* TTT
 512G (Glu-104)A (Lysd)A (Lys)
 604* GGG
 660A (His-153)G (Arg)G (Arg)
 682* CCC
 914G (Gly-238)A (Ser)G
 925* AAA
  • a Nucleotide numbering is according to that given by Sutcliffe (23) and amino acid numbering is according to Ambler et al. (1).

  • b Nucleotides marked with an asterisk are involved in the differences between bla TEM-2,bla TEM-1A, and bla TEM-1Bgenes (9, 10, 23).

  • c Gln for TEM-1.

  • d For TEM-21 and TEM-56, there are indicated amino acids differing from TEM-2.